Closure for connecting two thin walls

ABSTRACT

A closure, for connecting two thin walls, such as a sheet metal cabinet door to a sheet metal cabinet frame is disclosed, which comprises a bearing piece, arranged in or on an opening in the first thin wall and a shaft, retained in the bearing piece and which may be rotated and axially displaced therein. A pivoting lever is mounted on the on outer end of the shaft and, on the other inner end of the shaft, a retaining piece is arranged, which may be engaged with an opening in the second thin wall. The retaining piece comprises a cupular guide piece and a sleeve piece, which may be inserted in and rotated in the cupular guide piece against the force of a spring. A catch projects from said sleeve piece in the direction of the wall plane which, in the locked position, extends beyond the outer surface of the guide piece as far as the rear surface of the second thin wall and rests thereon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of International Application No.PCT/EP00/10613, filed Oct. 27, 2000 and German Application No. 299 22195.4, filed Dec. 17, 1999, the complete disclosures of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The invention is directed to a closure for connecting two thin walls,such as sheet metal cabinet doors to sheet metal cabinet frames, whichcomprises a bearing piece, mounted in or on an opening in the first thinwall and a shaft, retained in the bearing piece wherein it may berotated and axially displaced. A pivoting lever is mounted on the one,outer end of the shaft and, on the other, inner end of the shaft, aretaining piece is arranged, wherein the pivoting lever can be pivotedfrom a first, open position where the shaft is in a first axially loadedposition into a second, closed position where the shaft has beendisplaced axially outwards against the force of a spring.

b) Description of the Related Art

Such a closure is already known, cf. for example DE 44 23 406 A1.

The object referred to as an “Ausbauchverschluss” (convex or bellyingclosure) in this document makes it possible to secure two plate-likeparts to each other or one plate-like part to a corresponding frame. Theclosure described in this document has the advantage of greatsimplicity, since it needs relatively few parts and can be fittedrelatively simply.

Nonetheless, it also has disadvantages that forbid its use for certainapplications. Especially when the closure is supposed to work at lowtemperatures, as they are for example present in refrigerating chambers,resulting in the disadvantage that the body of expanded material, whichfor example consists of elastic rubber or plastic, loses its elasticitybecause of the low temperature and could even break if this leads tobrittleness.

There is the further disadvantage that the closure is immediately opencompletely when the operating lever is swung open accidentally, so thatthere is a risk that the two thin walls move apart unintentionally,which can for example lead to a refrigerating chamber being openedunintentionally.

OBJECT OF THE INVENTION

It is the primary object of the invention to improve a closure of thetype described in the opening section in such a way that the describeddisadvantages no longer occur.

In accordance with the invention, this object is met by making theretaining piece comprise a cupular guide piece and a sleeve piece, whichmay be inserted in and rotated in the cupular guide piece against theforce of a spring. A catch projects from said sleeve piece in thedirection of the wall plane which, in the engaged position, extendsbeyond the outer surface of the guide piece as far as the rear surfaceof the second thin wall and rests thereon.

First of all, these features avoid the use of a body of expandedmaterial, which at low temperatures might not be sufficiently flexibleanymore and therefore might lose its function or break during attemptsof use because of brittleness, and the ability of the two connectedwalls to move completely away from each other when the pivotingoperating lever is swung away is also removed. When the operating leverof the closure according to the invention is merely swung open, theclosure is opened and the connection of the two walls is loosened, butthe two walls can not be separated from each other; for this, the leverhandle must additionally be rotated, for example by 180 degrees.

Whereas in prior art the spring forces and locking forces must begenerated by the body of expanded material, resulting in the describeddisadvantages at low temperatures, the novel closure according to afurther development of the invention has the spring force beinggenerated by a spiral spring arranged between the bottom of the cup ofthe guide piece on one side and on the face of the sleeve facing thebottom of the cup on the other side. This spring is largely independentof temperature influences.

So that as in prior art the construction and installation are as simpleas possible, it is advantageous if the opening in the second thin wallis circular with two widening sections (for example corresponding to thecross-section of a two-way key) and if the catch part can be slidthrough the opening like a bayonet in one rotary position of therotating sleeve part but not in another position, for example onerotated by 90 degrees.

If one wants to avoid the expense of producing a two-way key opening inthe door-frame, according to another embodiment form the shaft could beguided through the bottom of the cup in a location that is eccentricrelative to the circumference of the cup. This makes it possible for thecatch to engage behind the wall in a first rotary position, while in asecond rotary position the catch can be passed through the opening.

According to yet another embodiment form of the invention, the lever canform a cam surface that rests on the outer face of the bearing piece.For prior art, the corresponding support is formed by the thin wallitself, which simplifies construction, but on the other hand can lead tounsightly paint damage that can lead to the formation of rust in visibleplaces.

The outer face of the bearing piece can form a groove shaped like partof a circle or a conical depression into which lugs, carried or formedby the lever, extend during its closing pivoting movement. This makes itpossible to only allow the closing pivoting movement of the lever insuch a position that is optimally suitable, whereas in other positionsthe pivoting of the lever is not possible because of the lack of agrooved area. This has the advantage that a closing pivoting movement isonly possible in a position where the catch engages sufficiently safelybehind the second wall.

According to yet another embodiment of the invention, the sleevecarrying the catch is held on the shaft by a self-locking nut. This hasthe advantage that the closing force can be set as required by way ofscrewing the nut further onto or off the bolt.

According to yet another embodiment of the invention, it can also beadvantageous to place a spring washer between the self-locking nut andthe catch sleeve for the purpose of compensating for small differencesin tolerance.

According to yet another embodiment of the invention, it is advantageousfor the outside of the bottom of the cupular part to have a projectionwhich is matched by a correspondingly shaped opening in the thin wall insuch a way that the cupular part is secured against rotation relative tothe thin wall; this is to ensure that the cupular part does not twistrelative to the thin wall and in so doing makes a closing positionindefinable.

The projection could in particular have a non-round cross-section whichfits into an opening in the thin wall which also has a non-roundcross-section and thus is secured against twisting.

Alternatively, the thin wall could also have additional openings intowhich lugs coming from the bearing protrude, but this does requireadditional openings in the thin wall, which sometimes are impractical.

Instead of the lug or the several lugs, threaded boreholes can beprovided into which (countersunk head-) screws can be screwed which comefrom the bearing or which can be passed through corresponding boreholesin the bearing.

This design is particularly tamper-proof.

A simple construction is made possible when according to another furtherdevelopment of the invention the opening in the first wall is anelongated hole into which the cross-section of the shaft fitsessentially without any play. By this, securing it against rotation isachieved without additional boreholes, and the opportunity for adaptingto different conditions also exists.

This is in particular the case if the opening in the first wall is anelongated hole into which the cross-section fits with play.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is subsequently to be described in more detail by means ofembodiment examples shown in the drawings.

FIG. 1 shows an exploded view of an embodiment form of the closure forthe connection of two thin walls according to the invention, which hereare a sheet metal cabinet door and a sheet metal cabinet frame;

FIG. 2 shows a cross-sectional view whose sectional plane is close tothe outside surface of the first thin wall;

FIG. 3 shows in a representation similar to FIG. 2 an alternativeembodiment form of the closure according to the invention which issecured against rotation by means of an elongated hole so thatadditional boreholes in the door leaf are not necessary;

FIG. 4 shows a cross-sectional view similar to FIG. 2 for therepresentation of an embodiment form;

FIG. 5 shows a view similar to FIG. 4 for the representation of anotherembodiment form;

FIG. 6 shows a perspective view of the arrangement according to FIG. 3,but in the assembled state, wherein the closure can be seen in the swungopen position;

FIG. 7 shows a perspective view of the closure shown in FIG. 6 but withthe handle swung in;

FIG. 8 shows the handle according to the invention in partial FIGS. A,B, C and D, wherein the different partial Figures show different phasesof opening:

FIG. 8A shows the closure in the closed position;

FIG. 8B shows the lever handle swung up and consequently the loosenedclosure;

In FIG. 8C, the handle has been rotated by 180 degrees so that accordingto FIG. 8D the two thin walls can be separated from each other and, forexample, the door leaf can be swung away from the door frame.

FIG. 9 shows the bearing piece of the closure according to FIG. 3 in aview from above;

FIG. 10 shows a closure according to another, bayonet-like embodimentform in the closed position in a side view;

FIG. 11 shows the closure from FIG. 10 in a partially sectional view inthe opened position; and

FIG. 12 shows diagrammatically the two-way key form of the opening inthe second wall (door frame) and the matching retaining part in theopened and closed position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an exploded view of a closure 10 with which two thin walls,like for example a sheet metal cabinet door 12 and a sheet metal cabinetframe 14 can be connected.

The closure comprises a bearing piece 18 arranged in or on an opening 16in the first thin wall 12 and a shaft 20, retained in the bearing piecewherein it may be rotated and axially displaced. A pivoting lever 24,which can be pivoted on an axis 28 that is vertical to the axis 26 ofthe shaft 20 is mounted on the one outer end 22 of the shaft 20, forexample held by a pin 30, which on one side is inserted in a borehole 32in the jointed end of the lever 24 and on the other side is inserted ina transverse bore 34 on the end of the shaft 20 and which is securedappropriately.

On the other, inner end 36 of the shaft 20, a retaining piece 38 isarranged, wherein the pivoting lever 24 can be pivoted from its first,open position, for example shown in FIG. 6, where the shaft is in afirst axial thrust exerting position, into a second, closed position—cf.FIG. 7—where the shaft is displaced axially outward (towards thepivoting lever 24) against the force of a spring 40.

The retaining piece 38 comprises a cupular guide piece 42 and a sleevepiece 44, which may be inserted and rotated in the cupular guide piece42 against the force of a spring 40; a catch 46 bent back towards thewall plane 50 projects from said sleeve piece 44 and, in the lockedposition, extends beyond the outer surface 48 of the guide piece 42 asfar as the rear surface 50 of the second thin wall 14 and rests thereon,cf. for example FIG. 7 and FIG. 8A.

As already mentioned, the spring force is generated by a spring 40 whichhas been slid onto the shaft 20 and which can be arranged between thebottom of the cup (not shown) on one side and the annular face 52 of thesleeve 44 facing the bottom of the cup. The annular face could here alsohave a ring-shaped groove into which part of the spring penetrates,giving it a greater longitudinal extent, so that the spring effect ofthe pressure spring 40 can be more even.

From the cup-bottom of the cupular guide piece 42 a projection 55protrudes (cf. FIG. 3) which on one side delimits the opening 56provided in the cup-bottom for the shaft 26 in such a way that togetherthey result in an elongated, non-round cross-section, cf. thecross-section according to FIG. 2. This joint oval, elongatedcross-section has a bisecting line 58 which defines a center line andwhich varies from a corresponding bisecting line 60 of the cross-section56 of the shaft 20 by a certain quantity 62. When assembled, the twocross-sections 54, 56 are housed by an opening 64 in the bearing piece18 which is also non-round and of a matching shape. In consequence, theshaft 20 is arranged eccentrically by the quantity 62 relative to thebearing piece 18 and the guide piece 42 housed by it. This has theconsequence that in the position of the lever to be seen in the FIGS. 8Aand 8B the catch protrudes beyond the outside wall 48 of the guide piece42 by a distance which is roughly equivalent to double the eccentricity62; but in a direction 180 degrees opposite to this (cf. FIGS. 8C and8D), it is flush with this outside wall, so that in this position thetwo pieces 42 and 46 can be passed through the opening 66 which isslightly larger than the cupular component 42 so that according to FIG.8D the thin wall 14, which is for example the door frame, can beseparated from the wall 12, which is for example the door leaf; cf. thearrow 68 in FIG. 8D.

To ensure that for a rotating movement of the lever handle 24 (cf. thearrow 70 according to FIG. 8C) the eccentric movement between the sleevepiece 44 holding the catch 46 on one side and the guide piece 42 guidingthe sleeve 44 on the other side actually occurs, it must be ensured thatthe sleeve piece 44 can not twist relative to the door leaf or the thinwall 12. According to the embodiment form in FIG. 1, this is done byholding the projection (together with the shaft 20) in the correspondingnon-round cross-section of the bearing piece 18 in such a way that atorsion-proof connection results between the components 42 and 18. Inturn, the piece 18 can be connected to the door leaf 12 in a manner thatis torsion-proof; for example by means of additional openings 72, 74 inthe thin wall through which either toes 78 projecting from thesupporting surface 76 of the bearing piece 18 on the thin wall 12 areinserted into boreholes 72, 74, or by fixing screws 80 coming from thebearing surface 76 in threaded boreholes, wherein in turn the cap screws80 may be guided through the openings 72 or 74.

For this type of attachment, it does not matter what shape the opening16 has, as long as there is a sufficient amount of space for the passageof the joint cross-section of the shaft 20 and the projection 55, cf.FIG. 2.

Nonetheless, according to FIGS. 3 and 4, the design is such that theopening 116 has exactly the same shape as the cross-section of theprojection and the shaft so that here the bore itself makes a securingagainst rotation possible. By means of this, additional component partslike projections 78 and screws 80 are no longer necessary. The need forcorresponding openings 72, 74 in the door leaf 112 also no longerapplies.

Even if there is some residual play between this cross-section and thecorresponding opening 216 according to FIG. 5, in particular indirection of the axis 83 according to FIG. 5, the elongated shape of thejoint cross-section of shaft and projection prevents twisting insidethis elongated borehole 216; on the other hand, a movement inside thiselongated borehole 216 along its longitudinal axis is made possible;this can be advantageous for certain applications, for example when thedoor 112 and the door frame 114 have been warped relative to each otherso that the two openings 116 and 216 do not align with each otherexactly any more. This makes closing the arrangement easier; what alsomakes the closing process easier is the fact that the catch 46 shown inFIG. 3 on the one hand and a corresponding portion 84 of the guide piece42 on the other hand are shaped like a cone.

As can be gathered from the Figures, the lever 24 forms a cam surface 86which rests on the outer face 88 of the bearing piece 18. As it is knownin the art, this cam surface 86 has such a shape relative to the axis 28that the desired traction movement results during the pivoting of thelever 24. To ensure that the closing movement of the lever 24, meaningthe movement from the position according to FIG. 8A to the one accordingto FIG. 8B, arrow 90, can only take place when the catch 46 is in theprotruding position according to FIG. 8B, provisions have been made forthe outer face 88 of the bearing piece to form a groove shaped like partof a circle or a depression 92 into which a lug 94 carried or formed bythe lever 24 extends during its closing pivoting movement, cf. FIGS. 6and 7. By means of this, the inwards pivoting movement for tighteningthe closure and therefore for pressing the catch against the insidesurface of the thin wall 14 can only take place in a position where thecatch front face can actually grip this wall; this is the position shownin FIG. 8B.

Because the lug forms an obstruction, the absence of the depression orof the groove formed like part of a circle prevents the inward pivotingof the lever 24 if the lever handle 24 is not in this optimal position.

What also should be mentioned is the flattened portion 96 on the end ofthe shaft 20 which can be made out in FIG. 1 and which facilitates itsimproved guidance between the side walls 98 of the slit formed by thelever 24.

A ring-shaped groove 100 in the shaft 20, which also can be made out inFIG. 1, can be used for providing an O-ring seal 101. The other end 36of the shaft 20 has a peripheral thread 102, also with a flattenedportion 103, so that a torsion-proof attachment of the sleeve piece 44is made possible because of a correspondingly shaped non-round opening104, while the self-locking nut 105 makes setting the tightness of theclosure possible. If one then arranges a spring washer 106 between theself-locking nut on one side and the sleeve piece 44 on the other side,tolerances of, for example, the thickness of the walls 112, 114, can becompensated for; cf. FIG. 3.

FIG. 9 shows the groove shaped like part of a circle 52, here in theshape of a short depression with wedge-shaped walls, into which acorresponding wedge-shape of the projection 94 fits precisely.

The wedge-shape ensures that the inward pivoting movement requires nogreat effort, even when the lever 24 is not aligned precisely.

According to FIG. 3, a groove 107 has been made in the surface withwhich the bearing piece 118 rests on the thin wall 112 into which anO-ring seal 108 can be inserted. If additionally the aforementionedsealing washer 101 is provided in the groove 100, the arrangement ismade waterproof by means of this.

FIG. 10 shows the side view of a closure 110 according to another,bayonet-like embodiment form in the closed position, while FIG. 11 showsthe closure 110 in a partially sectional view in the opened position.The first thin wall 112 and the second thin wall 114 here have roundholes of the same size, but the round hole in the second thin wall hasadditionally been provided with two wider portions lying opposite toeach other (for example, corresponding to the cross-section of a two-waykey), so that in one rotary position of the rotating sleeve 144, thecatch 146 can be passed through the opening like a bayonet, but not inanother position which, for example, is offset by a rotation of 90degrees.

Here also, the bearing piece 118 is screwed to the first thin wall 112by means of countersunk head screws 180; the other parts are alsoprovided analogously, as can be gathered from the references to whichthe prefix “1” has been added.

FIG. 12 shows diagrammatically the two-way key shape of the opening inthe second thin wall (doorframe) 114 and the matching retaining piece138, in the opened and in the closed position.

Although the expense at which the two-way key opening in the door frameis produced is a little bit higher than for a plain round opening likethe one according to the embodiment form in FIG. 1, the shape of theclosure is on the other hand a little bit simpler.

The invention can be applied industrially in the field of switch cabinetconstruction.

While the foregoing description and drawings represent the presentinvention, it will be obvious to those skilled in the art that variouschanges may be made therein without departing from the true spirit andscope of the present invention.

What is claimed is:
 1. A closure for connecting two thin walls, like asheet metal cabinet door and a sheet metal door frame to each other,comprising: a bearing piece being arranged in or on an opening in afirst thin wall, such as a door; a shaft being retained in the bearingpiece and which may be rotated and axially displaced therein; on anouter end of said shaft, a pivoting lever being mounted, which can bepivoted on an axis that is vertical to an axis of the shaft; on an innerend of the shaft, a retaining piece being arranged, wherein the pivotinglever can be pivoted from a first open position in which the shaft is ina first axial thrust exerting position, into a second closed position inwhich the shaft is displaced axially outward towards the pivoting leveragainst the force of a spring; said retaining piece comprising a cupularguide piece and a sleeve piece, which may be inserted in and rotated inthe cupular guide piece against the force of a spring; a catchprojecting from said sleeve piece in the direction of the wall plane;and in a locked position, the projecting of the catch extends beyond anouter surface of the guide piece as far as a rear surface of a secondthin wall and rests thereon; wherein a sleeve bearing and a catch sleeveare held on the shaft by a self-locking nut.
 2. The closure according toclaim 1, wherein an opening arranged in the second thin wall is circularwith widening portions preferably arranged opposite to each other andwherein the catch can, in the manner of a bayonet, be passed through anopening in a first rotary position of a rotating sleeve but not inanother position.
 3. The closure according to claim 1, wherein the leverforms a cam surface which rests on an outside face of the bearing piece.4. The closure according to claim 1, wherein an outside face of thebearing piece forms a groove in the shape of part of a circle or of aconical depression into which a lug formed or carried by the lever dipsduring the closing pivoting movement of the lever.
 5. The closureaccording to claim 1, wherein a spring washer is arranged between theself-locking nut and the catch sleeve.
 6. The closure according to claim1, wherein the outside surfaces of the catch or the cupular guide piecehave a conical shape.
 7. The closure according to claim 1, whereinsealing devices are provided which seal off spaces separated by thefirst thin wall from each other.
 8. The closure according to claim 1,wherein the spring force originates from a spiral pressure springarranged between the cup bottom of the guide piece on one side and theannular face of the sleeve pointing towards the cup bottom.
 9. Theclosure according to claim 8, wherein the catch is passed through theopening at a 90 degree rotary offset.
 10. The closure according to claim8, wherein the shaft is eccentric relative to the outside circumferenceof a cup.
 11. The closure according to claim 1, wherein the thin wallhas openings into which lugs protruding from the bearing piecepenetrate.
 12. The closure according to claim 11, wherein instead of thelugs, threaded boreholes are provided into which countersunk headscrews, can be screwed which have been passed through the openingsprovided in the first thin wall.
 13. The closure according to claim 1,wherein a projection extends from the outside of the bottom of thecupular piece which can be received by a correspondingly shaped openingin the thin wall in such a way that the cupular guide piece is securedagainst rotation relative to the first thin wall.
 14. The closureaccording to claim 13, wherein the projection has a non-roundcross-section which can be held by the opening in the thin wall with anon-round cross-section in a manner that is secured against twisting.15. The closure according to claim 13, wherein the opening in the firstthin wall is an elongated hole which can hold a cross-section of theprojection and the shaft without play.
 16. The closure according toclaim 13, wherein the opening in the first thin wall is an elongatedhole which can hold the cross-section of the projection and the shaftwith some play.
 17. A closure for connecting two thin walls, like asheet metal cabinet door and a sheet metal door frame to each other,comprising: a bearing piece being arranged in or on an opening in afirst thin wall, such as a door; a shaft being retained in the bearingpiece and which may be rotated and axially displaced therein; on anouter end of said shaft, a pivoting lever being mounted, which can bepivoted on an axis that is vertical to an axis of the shaft; on an innerend of the shaft, a retaining piece being arranged, wherein the pivotinglever can be pivoted from a first open position in which the shaft is ina first axial thrust exerting position, into a second closed position inwhich the shaft is displaced axially outward towards the pivoting leveragainst the force of a spring; said retaining piece comprising a cupularguide piece and a sleeve piece, which may be inserted in and rotated inthe cupular guide piece against the force of a spring; a catchprojecting from said sleeve piece in the direction of the wall plane;and in a locked position, the projecting of the catch extends beyond anouter surface of the guide piece as far as a rear surface of a secondthin wall and rests thereon; wherein the spring force originates from aspiral pressure spring arranged between the cup bottom of the guidepiece on one side and the annular face of the sleeve pointing towardsthe cup bottom.
 18. A closure for connecting two thin walls, like asheet metal cabinet door and a sheet metal door frame to each other,comprising: a bearing piece being arranged in or on an opening in afirst thin wall, such as a door; a shaft being retained in the bearingpiece and which may be rotated and axially displaced therein; on anouter end of said shaft, a pivoting lever being mounted, which can bepivoted on an axis that is vertical to an axis of the shaft; on an innerend of the shaft, a retaining piece being arranged, wherein the pivotinglever can be pivoted from a first open position in which the shaft is ina first axial thrust exerting position, into a second closed position inwhich the shaft is displaced axially outward towards the pivoting leveragainst the force of a spring; said retaining piece comprising a cupularguide piece and a sleeve piece, which may be inserted in and rotated inthe cupular guide piece against the force of a spring; a catchprojecting from said sleeve piece in the direction of the wall plane;and in a locked position, the projecting of the catch extends beyond anouter surface of the guide piece as far as a rear surface of a secondthin wall and rests thereon; wherein an outside face of the bearingpiece forms a groove in the shape of part of a circle or of a conicaldepression into which a lug formed or carried by the lever dips duringthe closing pivoting movement of the lever.